[New] Handle find and findAll error

Author: eddyerburgh

Diff for: flow/wrapper.js

@@ -4,18 +4,18 @@ import type Wrapper from '../src/Wrapper'
 import type WrapperArray from '../src/WrapperArray'
 
 declare interface BaseWrapper { // eslint-disable-line no-undef
-    at(index: number): Wrapper,
-    contains(selector: String | Component): boolean,
-    hasAttribute(attribute: string, value: string): boolean,
-    hasClass(className: string): boolean,
-    hasProp(prop: string, value: string): boolean,
-    hasStyle(style: string, value: string): boolean,
+    at(index: number): Wrapper | void,
+    contains(selector: String | Component): boolean | void,
+    hasAttribute(attribute: string, value: string): boolean | void,
+    hasClass(className: string): boolean | void,
+    hasProp(prop: string, value: string): boolean | void,
+    hasStyle(style: string, value: string): boolean | void,
     find(selector: string | Component): Wrapper | void,
     findAll(selector: string | Component): WrapperArray | void,
     html(): string | void,
-    is(selector: string | Component): boolean,
-    isEmpty(): boolean,
-    isVueInstance(): boolean,
+    is(selector: string | Component): boolean | void,
+    isEmpty(): boolean | void,
+    isVueInstance(): boolean | void,
     name(): string | void,
     text(): string | void,
     setData(data: Object): void,
@@ -25,5 +25,6 @@ declare interface BaseWrapper { // eslint-disable-line no-undef
 }
 
 declare type WrapperOptions = { // eslint-disable-line no-undef
-    attachedToDocument: boolean
+    attachedToDocument: boolean,
+    error?: string
 }

Diff for: src/ErrorWrapper.js

@@ -0,0 +1,60 @@
+// @flow
+
+export default class ErrorWrapper implements BaseWrapper {
+
+  at (): void {
+  }
+
+  contains (): void {
+  }
+
+  hasAttribute (): void {
+
+  }
+
+  hasClass (): void {
+  }
+
+  hasProp (): void {
+  }
+
+  hasStyle (): void {
+  }
+
+  findAll (): void {
+  }
+
+  find (): void {
+  }
+
+  html (): void {
+  }
+
+  is (): void {
+  }
+
+  isEmpty (): void {
+  }
+
+  isVueInstance (): void {
+  }
+
+  name (): void {
+  }
+
+  text (): void {
+
+  }
+
+  setData (): void {
+  }
+
+  setProps (): void {
+  }
+
+  trigger (): void {
+  }
+
+  update (): void {
+  }
+}

Diff for: src/Wrapper.js

@@ -6,6 +6,7 @@ import findVueComponents from './lib/findVueComponents'
 import findMatchingVNodes from './lib/findMatchingVNodes'
 import VueWrapper from './VueWrapper'
 import WrapperArray from './WrapperArray'
+import ErrorWrapper from './ErrorWrapper'
 
 export default class Wrapper implements BaseWrapper {
   vnode: VNode;
@@ -136,11 +137,17 @@ export default class Wrapper implements BaseWrapper {
       }
       const vm = this.vm || this.vnode.context.$root
       const components = findVueComponents(vm, selector.name)
+      if (components.length === 0) {
+        return new ErrorWrapper()
+      }
       return new VueWrapper(components[0], this.options)
     }
 
     const nodes = findMatchingVNodes(this.vnode, selector)
 
+    if (nodes.length === 0) {
+      return new ErrorWrapper()
+    }
     return new Wrapper(nodes[0], this.update, this.options)
   }
 

Diff for: test/unit/specs/mount/find.spec.js

@@ -6,6 +6,7 @@ import ComponentWithSlots from '../../../resources/components/component-with-slo
 import ComponentWithVFor from '../../../resources/components/component-with-v-for.vue'
 import Component from '../../../resources/components/component.vue'
 import Wrapper from '../../../../src/Wrapper'
+import ErrorWrapper from '../../../../src/ErrorWrapper'
 
 describe('find', () => {
   it('returns an array of Wrappers of elements matching tag selector passed', () => {
@@ -102,10 +103,17 @@ describe('find', () => {
     expect(() => wrapper.find(ComponentWithoutName)).to.throw(Error, message)
   })
 
-  it.skip('returns an empty Wrapper if no nodes matching selector are found', () => {
+  it('returns empty Wrapper with error if no nodes are found', () => {
     const wrapper = mount(Component)
-    const secondChildComponents = wrapper.find('pre')
-    expect(secondChildComponents.length).to.equal(0)
+    const selector = 'pre'
+    const error = wrapper.find(selector)
+    expect(error).to.be.instanceOf(ErrorWrapper)
+  })
+
+  it('returns empty Wrapper with error if no nodes are found when passed a component', () => {
+    const wrapper = mount(Component)
+    const error = wrapper.find(ComponentWithChildComponent)
+    expect(error).to.be.instanceOf(ErrorWrapper)
   })
 
   it('throws an error if selector is not a valid selector', () => {

Diff for: test/unit/specs/mount/findAll.spec.js

@@ -133,10 +133,11 @@ describe('findAll', () => {
     expect(() => wrapper.findAll(ComponentWithoutName)).to.throw(Error, message)
   })
 
-  it.skip('returns an empty array if no nodes matching selector are found', () => {
+  it('returns VueWrapper with length 0 if no nodes matching selector are found', () => {
     const wrapper = mount(Component)
-    const secondChildComponents = wrapper.findAll('pre')
-    expect(secondChildComponents.length).to.equal(0)
+    const preArray = wrapper.findAll('pre')
+    expect(preArray.length).to.equal(0)
+    expect(preArray.wrappers).to.deep.equal([])
   })
 
   it('throws an error if selector is not a valid selector', () => {